ashtrans Posted November 22, 2005 Share Posted November 22, 2005 ! aftermarket 4.75 ratio, not sure who it was made by though. To be fair this was a very wierd 6 wheel drive, independant suspension, amphibious vehicle, quite heavy as well ! Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted November 22, 2005 Share Posted November 22, 2005 Hi Dave, what's the deal? Is the reason that the ring gear is narrower (is it?), meaning it can flex more easily and be pushed away from the pinion. (Cue slipper pad? - could this not solve it?). Or is it to do with the number of teeth which mesh with the pinion gear at any given moment? (Less teeth = more force per tooth = bang?) Or something else? Why do you reckon they fail? I guess 6 wheel drive only shares the torque out further, so that's another sign of it's weakness? [ By the way - apparently a crate arrived which I guess is from you (I'm abroad at the mo). So thanks for that - bloomin' nice of you to sort me out. Cheers. ] Lots of questions I'm afraid!?! Al. Quote Link to comment Share on other sites More sharing options...
LR90 Posted November 22, 2005 Share Posted November 22, 2005 Dave, understood, that looks like my 4.7 BUT... there's plenty of trucks on here have had good success with 4.75s (Read Bros, Tonk, Jez, Ripley,.) so while they might not be the srongest they are better than stock 4.7 and provide excellent gearing with 35" tyres and a 1.2 (or thereabouts) xfer box). For those like me on a tight budget I can upgrade one axle at a time (can't do that with 4.11s) and with the 1.2 xfer box I get a low first ratio of 56:1 and still have the options (without effecting hi gears) of fitting your crawler gears or an underdirve. So while I would accept a health warning, "not as strong as 3.54", they are clearly in demand and are on the whole performing well. Quote Link to comment Share on other sites More sharing options...
ashtrans Posted November 22, 2005 Author Share Posted November 22, 2005 Hi Dave, what's the deal? Is the reason that the ring gear is narrower (is it?), meaning it can flex more easily and be pushed away from the pinion. (Cue slipper pad? - could this not solve it?).Or is it to do with the number of teeth which mesh with the pinion gear at any given moment? (Less teeth = more force per tooth = bang?) Or something else? Why do you reckon they fail? I guess 6 wheel drive only shares the torque out further, so that's another sign of it's weakness? [ By the way - apparently a crate arrived which I guess is from you (I'm abroad at the mo). So thanks for that - bloomin' nice of you to sort me out. Cheers. ] Lots of questions I'm afraid!?! Al. "Is the reason that the ring gear is narrower (is it?), meaning it can flex more easily and be pushed away from the pinion. (Cue slipper pad? - could this not solve it?)." the ring gear should be thicker in theory but I guess pegging would have helped, "Or is it to do with the number of teeth which mesh with the pinion gear at any given moment? (Less teeth = more force per tooth = bang?)" Yes I think this is more the case I guess 6 wheel drive only shares the torque out further, so that's another sign of it's weakness? Yes but this was a strange vehicle, not sure of weight but I think it was well loaded, [ By the way - apparently a crate arrived which I guess is from you (I'm abroad at the mo). So thanks for that - bloomin' nice of you to sort me out. Cheers. ] No prob but to be honest I don't remember making an invoice out to Astro Al ! "BUT... there's plenty of trucks on here have had good success with 4.75s (Read Bros, Tonk, Jez, Ripley,.) so while they might not be the srongest they are better than stock 4.7 and provide excellent gearing with 35" tyres and a 1.2 (or thereabouts) xfer box)." definatly better than stock and yes this may have just failed due the vehicle weight, I don't have any details of what it was doing, "For those like me on a tight budget I can upgrade one axle at a time (can't do that with 4.11s) and with the 1.2 xfer box I get a low first ratio of 56:1 and still have the options (without effecting hi gears) of fitting your crawler gears or an underdirve. So while I would accept a health warning, "not as strong as 3.54", they are clearly in demand and are on the whole performing well." agreed, fair comment, Quote Link to comment Share on other sites More sharing options...
jules Posted November 23, 2005 Share Posted November 23, 2005 That gear only looks to be about a 1/3 the thickness of the Kam ones I have not looked at any others. Quote Link to comment Share on other sites More sharing options...
istruggle2gate11 Posted November 23, 2005 Share Posted November 23, 2005 (Cue slipper pad? - could this not solve it?)." Can you supply these as kit form? I would be quite happy to fit myself. Quote Link to comment Share on other sites More sharing options...
ashtrans Posted November 23, 2005 Author Share Posted November 23, 2005 That gear only looks to be about a 1/3 the thickness of the Kam ones I have not looked at any others. Hi, you are right Jules, this is a strange one made with the series 4.7 offset, it is being replaced by one with 3.54 offset like this : Quote Link to comment Share on other sites More sharing options...
ashtrans Posted November 23, 2005 Author Share Posted November 23, 2005 Can you supply these as kit form? I would be quite happy to fit myself. Can do, if you are happy to do the install, we are doing this for a customer in Germany that does some racing, Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted November 23, 2005 Share Posted November 23, 2005 Can do, if you are happy to do the install,we are doing this for a customer in Germany that does some racing, Price, Dave? Quote Link to comment Share on other sites More sharing options...
ashtrans Posted November 23, 2005 Author Share Posted November 23, 2005 Price, Dave? £ 165 + VAT exchange, £ 25 core charge on the casing, please note you will have to turn down the OD of the diff centre to 164 mm, Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted November 23, 2005 Share Posted November 23, 2005 Hope your 4.1s I'm buying from you are a tad stronger ! Nige Quote Link to comment Share on other sites More sharing options...
ashtrans Posted November 23, 2005 Author Share Posted November 23, 2005 Hope your 4.1s I'm buying from you are a tad stronger ! Nige Likewise ! I think we have only had one 4.11 failure, this was in the US and the customer admitted the shop that installed it wasn't sure it was right and it ran too hot, Quote Link to comment Share on other sites More sharing options...
istruggle2gate11 Posted November 24, 2005 Share Posted November 24, 2005 Can do, if you are happy to do the install Hi Dave, How much just for the kit? Would save my "crude" plans! Roger Quote Link to comment Share on other sites More sharing options...
Lara Posted November 24, 2005 Share Posted November 24, 2005 Hi Dave, Did you know the owner of GGS owns a Lagonda like wot I sell? Lara. Quote Link to comment Share on other sites More sharing options...
ashtrans Posted November 24, 2005 Author Share Posted November 24, 2005 Hi Dave,How much just for the kit? Would save my "crude" plans! Roger Hi Roger, I would do a reworked casing at £ 165 + VAT, exchange, this would be for the casing, studs, nots and thrust pad, Lara, I knew you delt with him, I didn't know he had a Lagonda ! Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted November 24, 2005 Share Posted November 24, 2005 Hi Roger, I would do a reworked casing at £ 165 + VAT, exchange, this would be for the casing, studs, nots and thrust pad,Lara, I knew you delt with him, I didn't know he had a Lagonda ! Dave - is there a possibility to buy just the studs, nuts and thrust pad? I think there are people who could happily re-work the casing themselves. Cheers, Al. Quote Link to comment Share on other sites More sharing options...
ashtrans Posted November 24, 2005 Author Share Posted November 24, 2005 Dave - is there a possibility to buy just the studs, nuts and thrust pad? I think there are people who could happily re-work the casing themselves.Cheers, Al. not sure Al, 2 reasons : 1) the welding is very tricky, you need specific cast iron rods and some serious welding skill to get it right, and 2) I don't want to see pidgeon s**t welding and oil leaks and someone pointing to it saying it's an Ashcroft kit, load of c**p, this is not a dig at the DIYer but our welding guy has 35 years experience, a £ 12K TIG machine and we have only found 1 type of rod in the UK that will give a good result. If the weld is not good, the outer bracket will just crack off when the thrust pad gets a thump, Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted November 24, 2005 Share Posted November 24, 2005 not sure Al,2 reasons : 1) the welding is very tricky, you need specific cast iron rods and some serious welding skill to get it right, and 2) I don't want to see pidgeon s**t welding and oil leaks and someone pointing to it saying it's an Ashcroft kit, load of c**p, this is not a dig at the DIYer but our welding guy has 35 years experience, a £ 12K TIG machine and we have only found 1 type of rod in the UK that will give a good result. If the weld is not good, the outer bracket will just crack off when the thrust pad gets a thump, Yes sure - that's absolutely understandable as it could reflect on your company. I guess you just have to choose whether it's something you are prepared to supply on the basis that what people do with it - and how proficient the welding is - is entirely the responsibility of the owner. I honestly don't think anyone with a brain would blame Ashcrofts, when it's obviously nothing to do with you after you supply the bits, but then, not everyone has a brain worth talking about... Maybe you've encountered this sort of thing before? Well, let us know what you decide either way. Cheers, Al. Quote Link to comment Share on other sites More sharing options...
reads90 Posted November 24, 2005 Share Posted November 24, 2005 Hi, you are right Jules, this is a strange one made with the series 4.7 offset, it is being replaced by one with 3.54 offset like this : Hi The one on the left is a Kam 4.75 ring and the one on the right is a standard 90 ring Hell of a differance In the diffs Quote Link to comment Share on other sites More sharing options...
Ex Member Posted November 24, 2005 Share Posted November 24, 2005 (edited) Well, yes, it needs to be thicker as the pinion is smaller. It is the little pinion that is the problem. How about a picture of the pinions side by each. Edited November 24, 2005 by Red90 Quote Link to comment Share on other sites More sharing options...
Ex Member Posted November 24, 2005 Share Posted November 24, 2005 If I read KAM's site correctly, they make them all to fit Series diffs and thus need a spacer for coiler diffs. I thus assume the one Dave showed is a KAM unit. The M-D units are made for coiler diffs so are wider. http://www.kamdiffs.com/landrover_4_1.htm http://www.kamdiffs.com/landrover_4_75.htm Quote Link to comment Share on other sites More sharing options...
reads90 Posted November 24, 2005 Share Posted November 24, 2005 Well, yes, it needs to be thicker as the pinion is smaller. It is the little pinion that is the problem.How about a picture of the pinions side by each. Ok here you go Not alot of differance Quote Link to comment Share on other sites More sharing options...
Ex Member Posted November 24, 2005 Share Posted November 24, 2005 ???? Are you showing the comparison of the same units? Quote Link to comment Share on other sites More sharing options...
reads90 Posted November 24, 2005 Share Posted November 24, 2005 ???? Are you showing the comparison of the same units? the one on the left is standard 90 and the on the right is 4.75 kam Quote Link to comment Share on other sites More sharing options...
Ex Member Posted November 24, 2005 Share Posted November 24, 2005 (edited) Put the pinions closer together. There is a fair difference in diameter at the root of the gears. edit: I'm guessing the 3.54 pinion is 30 to 40% bigger in diameter. Tooth load (not stress) is proportional to contact radius. Edited November 24, 2005 by Red90 Quote Link to comment Share on other sites More sharing options...
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